For microfluidic processes such as inkjet printing, solid form compounds like pigmented colorants must be reduced in particle size from their original composition of preparation, which is commonly accomplished by milling using a liquid vehicle. Furthermore, the nascent fine particles must be simultaneously stabilized in the liquid medium as a colloidal dispersion by using a dispersant, such as a surfactant or a suitable polymer, to prevent aggregation and sedimentation. In order to produce especially fine particle size distributions on the nanometer size scale, micrometer scale milling media are agitated by high-speed stirring. The accelerated media collide with the compound to be milled, and the impact force results in de-aggregation or comminution. In one useful form, micromedia milling is a batch mixing process employing a high-shear impeller driven by a high-speed vertical mixer using polymeric resin beads (less than 300 micrometers diameter) to effect particle size reduction of the dispersion, which is typically comprised of solid compound, liquid vehicle, and particle stabilizer; U.S. Pat. No. 5,662,279 issued to Czekai et al., the disclosure of which is hereby fully incorporated by reference, is illustrative. Following the milling operation, the concentrated dispersion may conveniently be diluted and then separated from the milling media by filtration. The use of long-lived polymeric resin media minimizes the formation of mill attrition by-products that would contaminate dispersion. As the specific gravity of polymeric resin media is low and the resultant force from media-compound particle collisions is consequently reduced, however, a high proportion of media relative to solid compound is needed to produce desirable low average particle sizes, with narrow size distributions, at useful rates. Thus, the yield per batch of dispersion is substantially reduced relative to the total mixing vessel volume that is used in the milling process, and the separation of the liquid dispersion from the media bed is slow. If the media-to-dispersion ratio is decreased in order to charge the mixing vessel with more pigment dispersion to increase the overall batch yield, it is found that the same particle size distribution cannot be achieved in the normal period of time, if at all, so no net gain in productivity is possible. A need remains for an improved process that increases milling efficiency while simultaneously reducing milling media load, without compromise of dispersion particle size distribution.